重庆市空气污染持续过程特征及其气象成因分析

Analysis of Persistent Air Pollution Process and Its Meteorological Cause in Chongqing

利用空气质量日报数据分析了重庆市主城区空气质量的总体概况以及持续空气污染过程的特征,并着重探讨了2005年11月29日至12月31日期间的空气污染指数API变化及其与主要气象条件的相关关系。结果显示,一年中主城区出现连续3d以上空气污染指数API超过100的持续污染过程10次,累计污染超标日为61d,占全年总超标天数的61.6%;持续污染过程的气象条件往往有着共同的特点,即平均风速小,无降水或降水稀少,大气层结稳定,混合层高度较低。

The general situation of air quality and characteristics of persistent air pollution process in Chongqing urban area was investigated based on the dataset obtained from daily reports of air quality. The variation of Air Pollution Index （API） and its relationship with meteorological parameters during period from November 29 to December 31was discussed in more detail. The results showed that the occurrence frequency of persistent air pollution process, which is defined as continuous situation when API exceeds 100 more than three days, was 10 in 2005. The accumulated days of persistent air pollution process added up to 61, accounting for 61.6% of the total days when API exceeded 100.In general. There were some common meteorological conditions such as lower wind speed, non-precipitation or rare precipitation, stable air stratification, and lower mixed layer height that were predominated during the persistent air pollution process.